Apparatus and method for forming cartons



United States Patent Inventors George Schafer Santa Cruz; Ezra E. Theys,San Mateo; Hugh B. Morse, San Jose, California Appl. No. 735,000 FiledJune 6, 1968 Patented Oct. 27, 1970 Assignee Fibreboard Corporation SanFrancisco, California a corporation of Delaware.

APPARATUS AND METHOD FOR FORMING CARTONS 23 Claims, 21 Drawing Figs.

US. Cl 93/52, 53/375, 156/282, 156/497 Int. Cl .l B31b l/36 Field ofSearch. 93/52;

[56] References Cited UNITED STATES PATENTS 2,696,244 12/1954 Jackson156/497UX 3,084,489 4/1963 Seefluth 156/497X 3,340,777 9/1967Hittenberger et al.. 93/52X 3,347,014 10/1967 Mosse 156/282X 3,462,9168/1969 Chin 53/375 Primary Examiner-Bernard Stickney I AttorneyFryer,Tjensvold, F eix, Phillips & Lempio ABSTRACT: An apparatus comprises aconveyer for moving cartons along a line of flight, a horizontallydisposed folding Wheel rotatably mounted adjacent to the line of flightto fold the cartons end closure flaps and sealing means for subjectingthe flaps to aheated fluid and for compressing and sealing themtogether. The folding andsealing means are thereafter duplicated toclose and seal the cartons other end closure flaps after the carton hasbeen filled with a commodity.

Patented Oct. 27, 1970 FIG. 2.

INVENTOR. SCHA FER E THEYS B. MORSE ATTORNEYS Patented Oct. 27, 1970Sheet p n L u mw INVIiNT GEORGE SCHAI ER ATTORN EYS Patented Oct. 27,1970 I 3,535,987

4 I l% l FIG. 8.

l FIG: .9. 32

INVENTOR.

GEORGE .SCHAFER F a EZRA E. mars BY HUGH a. MORSE ATTORNEYS PatentedOct. 27, 1970 Sheet 4 of? INVENTOR.

GEORGE SCHAFER EZRA E THE Y5 BY HUGH B.

MORSE r I I ATTORN E YS Inf/- Patented Oct. 27, 1970 3,535,987

INVENTOR. GEORGE SCHAFER EZRA E THEYS BY HUGH 8. MORSE ATTORNEYSPatented Oct. 27, 1970 1 P; a: 2:? g g g 2 2 I 2 S E E 2 2/ GEORGE"kW/T9,? EZRA 5 THEKS BY HUGH a. MORSE ATTORNEYS APPARATUS AND METHODFOR FORMING CARTONS This application relates to an apparatus and methodsimilar in some respects to those disclosed in U.S. Pat. ApplicationSer. No. 457,893 for Apparatus and Method for Folding and SealingCartons, now U.S. Pat. No. 3,389,645 assigned to the assignee of thisapplication.

The popularity of single structure frozen food cartons obviates the needfor apparatus and methods whereby such cartons can be formedexpeditiously and efficiently. Many such cartons are coated withpolyethylene, for example, whereby the end flaps thereof may be folded,subjected to a heated fluid and compressed together to form a sealed endclosure. Conventional apparatus normally employ separate mechanisms foreffecting each folding function. Such apparatus are somewhatcomplicated, expensive to fabricate and operate and require a largenumber of periodic adjustments to maintain the various foldingcomponents in operative condition.

Regarding conventional carton flap sealing means, it has oftentimesproved difficult to precisely align and maintain the carton flaps inproper position during their run therethrough. In addition, cartonsurface portions oftentimes rub against metallic surfaces whereby thecarton is marred and the flaps thereof tend to become misaligned. Whensuch sealing means utilize a nozzle for discharging heated air onto thecarton flaps, the air is not always precisely imparted onto the criticalsealing areas of the carton flaps. Frozen food cartons, in particular,require a positive seal at each end thereof to prevent leakage of thepackaged contents.

The primary objects of this invention are to provide an apparatus andmethod for economically and efficiently forming cartons which willexhibit high leakage resistance. A flap folding means of the apparatusis horizontally disposed and rotatably mounted adjacent to the cartonflaps to perform the majority of the folding operations. The sealingmeans therefor preferably comprises air cushioning means for supportingand suspending a major flap adjacent to a nozzle bar which discharges aheated fluid onto the flaps prior to final sealing thereof.

Other objects of this invention will become apparent from the followingdescription and accompanying drawings wherein:

FIG. 1 schematically illustrates the folding and sealing apparatus ofthis invention employed in a conventional packaging machine;

FIG. 2 illustrates a partially formed carton adapted to have the endclosures thereof folded and sealed to form the completed carton of FIG.3;

FIG. 4 is an enlarged side elevational view of a flap folding meansemployed in the FIG. 1 apparatus with a cover plate thereof removed forclarification purposes;

FIG. 5 is a front elevational view of the FIG. 4 flap folding means;

FIG. 6 is a top plan view of a folding wheel employed in the FIG. 4 flapfolding means;

FIGS. 7 through are enlarged views taken in a direction of arrows 7-7,8-8, 9-9 and 10-10 in FIG. 6, illustrating specific constructionsemployed in the folding wheel;

FIGS. 11 through 15 are isometric views of the flap folding means as itwould appear during various stages of operation with FIG. 12 furtherillustrating a sealing means employed therewith to form a sealed endclosure;

FIG. 16 is an enlarged, cross-sectional view of the sealing means takenin the direction of arrows 16-16 in FIG. 12;

FIG. 17 is an enlarged, cross-sectional view of a nozzle bar and aircushion means employed in the sealing means;

FIGS. 18 and 19 are isometric views more clearly illustrating the nozzlebar and air cushion means, respectively, with only a limited number ofnozzles thereof illustrated; and

FIGS. 20 and 21 are bottom plan and front elevational views,respectively, of the FIG. 18 nozzle bar.

The packaging apparatus schematically illustrated in FIG. 1 comprises: aconventional carton feeding station A for transferring opened cartons toa conveying means; folding station B dispensing station D isconventional in that it may function to discharge a liquified productinto the top, open end of the carton after the bottom closure has beenformed at stations B and C. This invention is primarily concerned withthe construction and operation of stations B and C whereat the bottomflap folding and sealing functions occur. Since stations B and C areinverted duplicates of stations B and C, respectively, only the latterstations will be described hereinafter.

The vertically disposed cartons, opened to their FIG. 2 condition atstation A, are each transferred to the conveying means comprising spacedlugs 20 of an endless beit 21. The carton is then moved by the conveyoralong a horizontal path P through folding and sealing stations B and C.For purposes of the following description, the vertical and horizontaldisposition of various components may be considered as being relative topath P. However, it should be understood that such expressions arepurely relative and are not intended to limit the scope of thisinvention.

Referring to FIGS. 4-7, folding station B comprises a verticallydisposed tucker wheel 22 having a flap engaging notch 23 formed on theperiphery thereof. The tucker wheel is suitably splined or otherwiseconnected to a shaft 24 to rotate therewith. A bevel or right-angle gearconnection, schematically illustrated at 25, operatively connects shaft24 to a vertically disposed shaft connection 26 having a rotary foldingmeans or wheel 27 also connected thereto.

The drive connections for wheels 22 and 27 are adapted to be driven bythe main drive motor of the apparatus via suitable mechanisms. Suchdrive mechanisms and attendant construc tions may be of the typeillustrated in FIG. 2A of U.S. Pat. application Ser. No. 457.893 forApparatus and Method for Folding and Sealing Cartons, filed on Apr. l9,I965 by John D. Winters et al. and assigned to the assignee of thisapplication.

As will be hereinafter more fully described, a stationary holddown bar28 (FIG. 4) cooperates with tucker wheel 22 to correctly position minorflaps F, and F prior to filling. A support plate 29 is horizontallypositioned adjacent to wheel 27 to receive folded bottom closure flapsF,F thereon. A stationary bar 30 is positioned adjacent to flap F toprevent collapse of the carton thereat during folding of the flap. Asimilar bar (not shown) may be arranged adjacent to flap F, in a likemanner.

Referring to FIGS. 6-10, folding wheel 27 is substantially circular andis suitably constructed to fold and position flaps F,, F, and F A curvededge portion 31 is formed on the periphery of the wheel to have theradius thereof recede when the wheel rotates counterclockwise about itsaxis. A tapered first finger 32 and such edge portion form a V-shapednotch 33 adapted to aid in the positioning and folding of first orleading minor flap F, (FIG. 11). The leading edge of the finger issloped at 34 to permit the flap to gradually move onto a flat portion 35which is constructed to move under flap F, during folding.

A troughlike recess, defined on one side thereof by sloped surface 36,terminates at one end thereof at notch 33 and is adapted to permit flapF, to be folded without contacting the wheel. Folding of first majorflap F, inwardly towards the carton (FIG. 12) is then initiated bysurface 36. Continued rotation of the wheel and synchronized movement ofthe conveyor function to maintain folded flap F, on a large, flat area37 of the wheel. The periphery of the wheel is preferably chamfered at38 to continue and complete the folding of flap F A cutout portion 39 isformed on the edge of the wheel to permit flap F to fall therein forpurposes hereinafter explained. A second V-shaped notch 40 is formed inthe wheel to permit the trailing minor flap to be maintained andcaptured therein prior to folding thereof by a second finger 41.Simultaneously therewith cutout portion 39 permits leading minor flap Fto snap back, due to its inherent resiliency, to a substantiallyvertical position.

The conveying means will thereafter move the carton along path P topermit flap F to engage stationary plate 29 which functions to fold flapF 1 towards flap F and over flap F Substantially simultaneouslytherewith, flap F is folded over flap F 3 by finger 41 and the lattertwo flaps are held on flat portion 37 of the wheel and thereafter movedonto plate 29. Such flat portion is preferably disposed in a horizontalplane which substantially coincides with the horizontally disposed topsurface of support plate 29, but is slightly higher than flat surfaceportion 35 (FIG. 9).

From the above description it can be seen that wheel 27 performs anumber of folding functions previously accomplished by a plurality offolding means. In particular, the single wheel may be readily and simplyadjusted to precisely fold flaps F,F into superimposed position prior tosealing. It should be further noted that the wheel provides a verycompact folding mechanism which may have its largest radius positionedvery close (e.g., one-fourth inch) to second major flap F during thefolding sequence. The wheel is preferably synchronized with the conveyermeans via suitable drive mechanisms so that the wheel makes one completerevolution during the passage of each carton thereby. However, thevarious folding means formed on the wheel could be duplicated thereon tofold the flaps of two cartons pursuant to one revolution of the wheel,for example.

Referring to FIGS. 12 and 16-2l, a stationary plow bar 42, adjacent tosealing station C, functions to fold flap F into its proper FIG. 17position prior to scaling. The station comprises a carton sealing means43 having a nozzle bar or heating means 44 arranged to cooperate with anair cushion means 45 to hold flap F in such position during sealing. Thenozzle bar comprises a substantially V-shaped cross section defined by ahorizontally disposed and flat top surface 46 and a tapered and flatbottom surface 47.

The included angle X between the converging surfaces is preferablyselected from a range of from to 30. Such a narrow nozzle bar permitsthe flaps to be quickly sealed together after they have been subjectedto a heated fluid. In actual practice the underside of the nozzle bar'stip is preferably cut away and relieved to form a less pronounced bendin flap F than the bend illustrated in FIG. 17.

A series of first nozzles or jets 48 are formed on the top surface ofthe nozzle bar whereas a series of second nozzles 49 are formed at thebottom surface thereof. A series of third nozzles 50 are disposed at theinner end of the nozzle bar for purposes hereinafter explained. Topsurface 46 of the nozzle bar is preferably disposed in a plane which issubstantially parallel to a horizontally disposed plane containing pathP (FIG. 17).

Each nozzle 48 is preferably disposed at an angle y, relative to surface46, selected from the range of from 30 to 70. Nozzles 49 are disposed ata like angle with respect to surface 47. Such disposition of the nozzlesforces air towards the hingeline whereat flap F is connected to thecarton. The accumulated air assures a washing effect" over the cartonflap surfaces to provide an even and efficient distribution of theheated airstream.

A slotlike passage 51 communicates heated air to the orifices from achamber 52 formed in the heater illustrated in FIG. 16. Such heatercomprises a tubular neck or manifold 53 secured to a body or casing 54and preferably having baffie means (not shown) arranged therein to formthree separate airstreams to chamber 52. Primary and secondaryelectrical heating coils 55 and 56 are concentrically arranged in thecasing and suitably connected by leads 57 and 58 to an electrical powersource (not shown) via suitable control means (not shown) to heat thecoils to a predetermined temperature. The heater further comprises aninlet 59 for communicating ambient air to a chamber 60 and a firstannular passage 61.

The passage circumvents the coils except for the portions thereofwhereat tie rods 62 are arranged for securing the heater componentstogether. Passage, 61 in turn communic'ates with a second annularpassage 63 separated from passage 61 by a first cylindrical baffle 54ato preheat the air by means of secondary coils 56. The air then passesinto a third passage or main chamber 64, separated from chamber 63 by asecond cylindrical baffle 54b, containingprimary coils 55 and intooutlet passage 52. The outlet passage preferably comprises a modifiedventuri configuration to increase the velocity of the air prior to thetime it is discharged onto the carton flaps by the nozzle bar. Aircushioning means 45 (FIGS. 16, 17 and 19) comprises an air inlet 65adapted to communicate cool ambient air to a chamber 66 formed inhousing 67 thereof. Flat top surface 68 of the cushioning means isconstructed and arranged substantially parallel with respect to bottomsurface 47 of the nozzle bar. Orifices 69 are formed therethrough todischarge the relatively cool fluid, preferably air, onto the undersideof flap F Nozzles 69 are preferably arranged substantially perpendicularrelative to surface 68 and flap F It should be noted that each nozzle 69is preferably juxtaposed to a hot air nozzle 49. Such an arrangement hasbeen found to provide enhanced free-floating" or suspending effects onflap F to prevent marring and distortion thereof. Opposed surfaces 70and 71 are preferably constructed and arranged to center the cartonthercbetween with only surface 71 providing edge contact with thecarton. A roller 72 (FIG. 12) is rotatably mounted in the apparatus tocooperate with support rail 73 to fully compress the bottom closureflaps of the carton together. Holddown bar 28 cooperates therewith toassure that the flaps are subjected to suitable sealing pressures.

The preferred method of this invention will now be described withreference to the above described apparatus, although it should beunderstood that other forms of apparatus could be utilized to carry outthe various method steps. Conveyer 21 is arranged for conveying carton Calong line of flight P with flaps F,-F disposed substantially verticallydue to their inherent resiliency (FIG. ll). Notch 23 of rotary tucker 22is positioned for engaging and folding upper minor flap F, leftwardly toposition it under holddown bar 28. The smooth periphery of the tuckerthereafter folds upper minor flap F in the opposite direction and underthe bar to fully expose the top opening of the carton for fillingpurposes at station D.

Referring now to the folding steps occurring at wheel 27.counterclockwise rotation thereof positions first finger 32 for engagingand folding the lower, first and leading minor flap F onto flat portions35 and 37 of the wheel (FIG. I2). Sloped surface 36 and chamfer 38 arearranged for then progressively folding first major flap F inwardlytowards path P and second major flap F Upon completion of such folding,flap F, drops into cutout 39 due to its inherent resiliency (FIG. 13)and is thereafter folded in an opposite direction towards second minorflap F by engagement with stationary plate 29 (FIG. 14). Second finger41 is arranged for substantially simultaneously engaging and foldingflap F over flap F Superimposed flaps F,F are then carried onto plate29in their folded position (FIG. 15). Thereafter, second major flap Fengages stationary plow bar 42 for folding the flap to its FIGS. 16 and17 position prior to entrance into the sealing means. Tapered wallsurface 71 is suitably arranged for supporting an edge of the carton tofacilitate the step of inserting nozzle bar 44 between second major flapF and the other flaps. Orifices 48, 49 and 50 are arranged forefficientlyand evenly discharging a heated fluid, preferably air, ontothe flaps.

Orifices 68 of the air cushioning means are arranged for dischargingcool air onto the underside of flap F to suspend the flap between thenozzle bar and cushioning means. The air pressure on both sides of theflap is preferably equal due to the substantially identical orificeconfigurations of nozzles 49 and 69 Thus the flap is prevented fromcontacting metallic surfaces 47 and 68.

When metallic guide bars and the like are employed to position a flap bycontact therewith, they invariably absorb an appreciable amount of heatdue to their proximity to the nozzles. Thus the cartons are oftentimesmarked or otherwise scarred and frictional engagement with the surfacestends to pull the carton out of square The above-described method,whereby balanced air pressures function to suspend flap F allows theflap to be passed through the sealer with negligible resistance.

In addition, expeditious sealing of the carton flaps is readily achievedand the outside surface of flap F is left sufficiently cool so thatroller 72 (FIG. 12) or other suitable compression device does not mar orotherwise damage such surface. In particular, the cool air imparted tothe outside surface of flap F prevents the heat generated at nozzle bar44 from being conducted through the flap and to its outside surface.

We claim:

1. An apparatus for forming a carton end closure comprising conveyermeans for moving a carton along a horizontal line of flight with a pairof opposed minor flaps and a pair of opposed major flaps thereofmaintained substantially vertically, flap folding means. including awheel rotatably mounted about a substantially vertically disposed axisand positioned adjacent to said flaps for folding said pair of minorflaps and a first one of said major flaps into superimposed relationshipand sealing means for folding and securing the second one of said majorflaps over the other three flaps.

2. The invention of claim 1 wherein said wheel comprises a substantiallycircular configuration having first and second fingers positioned on theperiphery thereof to extend in the same circular direction forsequentially folding said minor flaps upon rotation of said wheel.

3. The invention of claim 2 wherein said first and second fingers arespaced approximately 90 apart about said vertically disposed axis.

4. The invention of claim 2 wherein said flap folding means furthercomprises a recessed portion formed on said wheel adjacent to said firstfinger portion for aiding in the folding of said first major flap.

5. The invention of claim 2 wherein said flap folding means furthercomprises a cutout portion formed on the periphery thereof adjacent tosaid second finger for receiving said first minor flap therein.

6. The invention of claim 1 further comprising a horizontally disposedplate positioned adjacent to said flap folding means for holding saidminor flaps and said first major flap in superimposed relationship afterthey have been folded by said flap folding meansv 7. The invention ofclaim 1 further comprising means for folding said second major flaptowards the other flaps and wherein said sealing means comprises heatingmeans for subjecting inner surface portions of said second major flapand surface portions of the other of said flaps to a heated fluid.

8. The invention of claim 7 wherein said sealing means further comprisesair cushioning means cooperating with said heating means for suspendingsaid second major flap therebetween.

9. In an apparatus for forming a carton end closure, conveyer means formoving a carton having end closure flaps along a horizontal line offlight, folding means for folding and superimposing said flaps, andsealing means for Securing a major flap hingedly connected by ascoreline to said carton over the other flaps, said sealing meanscomprising a V-shaped nozzle bar extending in the direction of said lineof flight and towards said scoreline and having converging flat top andbottom surfaces and a first and a second series of nozzles formed insaid nozzle bar to intersect said top and bottom surfaces, respectively.at an angle selected from the range of from 30 to 70, said first andsecond series of nozzles disposed on said nozzle bar to diverge awayfrom each other towards said scoreline to form an included angle betweensaid first and second series of nozzles which is substantially less thanl to discharge a heated fluid onto said flaps.

10. The invention of claim 9 wherein the top surface of said nozzle baris horizontally disposed relative to said horizontal line of flight.

11. The invention of claim 9 further comprising cushioning means fordischarging a cool fluid onto the underside of said major flap tosuspend said major flap between said nozzle bar and said cushioningmeans.

12. The invention of claim 11 wherein said cushioning means comprises aflat top surface arranged substantially parallel with respect to thebottom surface of said nozzle bar, and a series of nozzles terminatingat the top surface of said cushioning means adapted to discharge saidcool fluid therefrom.

13. The invention of claim 9 wherein said sealing means furthercomprises a heater for heating said fluid, said heater comprising aninlet, an outlet communicating with said first and second series ofnozzles of said nozzle bar, a plurality of electrical heating coils andpassage means for communicating fluid from said inlet, over saidelectrical heating coils and to said outlet.

14. The invention of claim 13 wherein said heating coils compriseprimary and secondary coils concentrically arranged in said heater andseparated by a cylindrical baffle.

15. In an apparatus for forming a carton end closure by folding andsecuring a major flap over other end closure flaps, a nozzle bar adaptedto be inserted between said major flap and the other flaps to dischargea heated fluid onto one side of said major flap and cushioning meanspositioned in opposed relationship to said nozzle bar for discharging acool fluid onto the other, opposite side of said major flap to suspendand maintain said major flap out of contact with said nozzle bar andsaid cushioning means.

16 The invention of claim 15 wherein said nozzle bar comprisesconverging top and bottom surfaces and said cushioning means comprises aflat top surface arranged substantially parallel with respect to a flatbottom surface of said nozzle bar.

17. The invention of claim 16 wherein said nozzle bar further comprisesa series of nozzles formed therein to terminate at the bottom surfacethereof and wherein said cushioning means further comprises a series ofnozzles formed therein to terminate at the top surface thereof insubstantial juxtaposed relationship with respect to the series ofnozzles formed in said nozzle bar.

18. In an apparatus for forming a carton end closure, means forsubjecting carton flaps to a heated fluid comprising a heater forheating said fluid to a predetermined temperature, said heatercomprising a tubular casing having first and second baffles positionedtherein and suitably spaced one from another to form a first passagebetween said casing and said first baffle, a second passage between saidfirst and second baffles communicating with said first passage and achamber within said second baffle communicating with said first passageand heating means positioned in at least one of said second passage andsaid chamber for heating air communicated through said first and secondpassages and into said chamber.

19. A method for forming a carton end closure, said carton comprisingjuxtaposed first and second minor flaps and juxtaposed first and secondmajor flaps, said method comprising the steps of:

conveying said carton along a line of flight;

folding said first and second minor flaps and said first major flap intosuperimposed relationship, including the step of rotating a singlefolding wheel to engage and fold said first major flap towards saidsecond major flap and to engage and fold said second minor flap oversaid first major flap and towards said first minor flap; and

sealing said second major flap over said first and second minor flapsand said first major flap.

20. The invention of claim 19 wherein said folding step further includesthe step of engaging said first minor flap with said folding wheel tofold it away from said second minor flap prior to when said foldingwheel engages said first major flap to fold it towards said second majorflap.

2L The invention of claim 19 wherein said sealing step includes thesteps of inserting a nozzle bar between said second major flap and theother flaps and simultaneously discharging a heated fluid onto saidflaps.

22 The invention of claim 21 wherein said sealing step further includesthe step of discharging cool air onto the un-

